In a semiconductor manufacturing process, a plasma processing apparatus configured to perform a plasma process for a thin film deposition or an etching is widely used. Such a plasma processing apparatus includes, for example, a plasma CVD (Chemical Vapor Deposition) apparatus configured to perform a thin film deposition process, a plasma etching apparatus configured to perform an etching process, and so forth.
Such a plasma processing apparatus includes a processing vessel for performing therein a plasma process on a processing target object, a sample table for holding the processing target object within the processing vessel, a gas supply system for introducing a required processing gas for a plasma reaction into the processing vessel, and so forth. Further, to excite the processing gas within the processing vessel into plasma, the plasma processing apparatus also includes a plasma generation device configured to supply electromagnetic energy such as a microwave or a RF wave, a bias voltage application device configured to apply a bias voltage to the sample table to accelerate ions in the plasma toward the processing target object held on the sample table, and so forth.
In the plasma processing apparatus, however, as the processing target object is plasma-processed, various kinds of deposits (reaction products, reaction by-products, etc) adhere to members (hereinafter, referred to as “in-vessel member”) provided within the processing vessel. These deposits may be etched to be dispersed as contaminants when a next substrate is processed. Further, as substrates are processed, the deposits may be deposited within the processing vessel and fall down later, so that particles are generated. Accordingly, the deposits need to be removed. In this regard, Patent Document 1 describes a technique of removing a metal-containing deposit, which is generated when a processing target object containing a metal film such as a transition metal is plasma-processed and adheres to in-vessel members, by using plasma of a chlorine-based gas or a nitrogen-based gas.
Patent Document 1: Japanese Patent Laid-open Publication No. 2006-179834
Patent Document 2: Japanese Patent Laid-open Publication No. 2006-165246
However, in the conventional technique of using the chlorine-based gas or the nitrogen-based gas, the metal-containing deposit may not be removed efficiently if a metal having resistance to the plasma of the chlorine based gas or the nitrogen-based gas is contained in the deposit.